Jeff Niemann and two relievers combined on a four-hit shutout and the Tampa Bay Rays had seven extra-base hits to blank the Seattle Mariners, 8-0, on Thursday night.

Tampa Bay swept the three-game series and improved to 12-1 on the road, the best road start in the majors since the Detroit Tigers went 17-0 in 1984.

The loss was Seattle’s sixth in a row.

Niemann (2-0) allowed four hits in seven innings with six strikeouts and two walks. Joaquin Benoit and Andy Sonnanstine each put the Mariners down in order in the eighth and ninth innings to preserve the shutout.

Carl Crawford hit a two-run homer in the eighth and also doubled. Third baseman Evan Longoria had an RBI double and extended his hitting streak to 12 games, tying his career-high. Willy Aybar and B.J. Upton also had RBI doubles.

Mariners starter Ryan Rowland-Smith (0-2) had his worst outing of the season, allowing six runs on seven hits in 4 1/3 innings.